Spark-plug for internal-combustion engines.



w. 0. VANDECAR. SPARK PLUG FOR INTERNAL COMBIISTION ENGINES.

APPLICATION FILED DEC- 17, I914.

Patented Nov. 21915.

@Imvantoz WILLIAM D. VANDECAR, OF GRAND RAPIDS, MICHIGAN.

SPARK-PLUG FOR INTERNAL-COMIBUSTION ENGINES.

To all whom it may concern:

Be it known that I, WILLIAM D. VANDE- GAR, a citizen of the United States, residing at Grand Rapids, in the county of Kent and State of Michigan, have invented certain new and useful Improvements in Spark- Plugs for Internal-Combustion .Engines, of which the following is a specification.

My invention relates to improvements in.

spark plugs for use in internal combustion engines, and its objects are: first, to provide a multiple spark plug without the necessity of placing an intermediate circle or post of metal between the point of the conductor wire and the end of the plug; second, to

provide a means whereby a multiple spark plug may be made wherein the spark producing breaks in the conductor wires may be protected from the direct action of the explosion and the direct damaging pressure of the gas explosion in the engine cylinder; third,to provide a means whereby the several sparks may be produced wholly within the plug, or partly within the plug and partly in the cylinder at the end of the plug, with equal efiiciency. I attain these objects by the construction and combination of parts shown in the accompanying drawing,

in which Figure 1 is a longitudinal section of the complete plug showing the relative positions of the several parts; Fig. 2 is an elevation of the complete plug; Fig. 3 shows a modified form of terminal wire for producing multiple sparks from a single conductor Wire; Fig. 4 shows detached terminal wires arranged to guard against missing a spark should one or more wires become corroded. Fig. 5 is the same showing the wires arranged for producing the sparks inside of the plug only; Fig. 6 is the same showing a double spark producer with one of the sparks inside of the plug, and the other spark outside of the plug; Fig. 7 shows the plug arranged for producing a single spark only, and that inside of the plug; Fig. 8 is a modified form of Fig. 3, and Fig. 9 shows an arrangement for multiple sparks.

Similar numerals and letters refer to similar parts throughout the several views.

The casing 1, retaining nut 2, cap 4, nut 5, and conductor wires 6 and 7, all of metal, and the porcelain insulator 3 are common elements in all spark plugs, and are disposed and connected practically as shown in Figs. 1 and 2 of the accompanying draw- Speeification of Letters Patent.

Patented Nov. 2, 1915.

Application filed December 17, 1914. Serial No. 877,798.

ing. My invention consists in cutting the conductor wire 7 shorter than the length of the casing 1, forming a hole 10 through the casing for the entrance and free passage of gas, and inserting an auxiliary porcelain plug 8 in the end of the casing so as to form a considerable space and an air chamber in the casing between the porcelain cores 3 and 8, and around core 3, practically as shown in the several figures. I place one or more wires, '9, in the porcelain 8, preferably extending into the space between the cores 3 and 8 so as to promote a spark within the casing 1 at the point a, as indicated in Figs. 1, 2 and 5 when a double spark is produced; one at a, and the other at b. In this construction the wires 9 should be insulated in such a manner that no heat, carbon or oil can interfere with the outer, or lower end of this wire. If it is desired to produce but a single spark within the casing the wire 9 may be grounded upon the casing 1 at any point between the openings 10 and the outer so a sparkwill'be formed at a and b. In,

Fig. 6 I have shown the wires arranged to form one spark at a and a second spark at o, the former inside of the casing and the lat ter outside of the casing. In Fig. 5 I have shown the outer ends of the wire 9 insulated by means of an insert, as f, so that no carbon or oil can come in contact with the end of thewire outside of the casing.

If the form of wire shown in Figs. 3 and 8 is used while but a single spark is produced at d, the multiplicity of the receiving points 03 will cause the spark to be much more intense than if a single receiving point is used, and the discharge from the several points d produces several distinct sparks, though their intensity is not as great as would be the case if but a single terminal m5 inside of the casing 1 is that any oil that may be deposited on the ends of the wires 7 and 9 will immediately drip down onto the end of the porcelain 8 and fiowout through the openings 10, and a second adinoperative at once, hence the chances of skipping a spark by reason of short circuiting through the collection of a carbon scale upon the surface of the insulating substance, as porcelain or other fire proof non-conductor of electricity, would be reduced to the minimum for the reason that at least one of the wires would remain active until proper cleaning and rearrangement of the others could be brought about.

It will be noticed that the relative positions of the wires 7 and 9" are the same in all instances so that a spark must, in all cases, be formed at a, within the casing, and

to positively insure the efficiency of such sparks the openings 10 must be of sufficient size to insure a full, free passing of gas and air to the spark points within the casing,

as at a, b, or 0 and d.

While porcelain is considered the most available and effective. insulator for use in spark plugs, it is to be understood that the use of any heat resisting, non-conductor of electricity may be made available in lieu of the porcelain hereinbefore shown and describe At 11 "in Fig. 5 I have shown a metal screen over the opening 10. This screen is designed for two purposes: first, to avert the danger of the formation of a carbon crust upon vthe surfaces of the insulating cores or the walls of the casing, or the wires 7 and 9 within the space between the ends of the porcelain cores 3 and 8, and, second, to avert the danger of oil being thrown upon the surfaces of the porcelain or the conducting wires where the electricspark is to be produced, thus doubly guarding against short circuiting the electric current and thereby destroying the spark producing qualities of the plug, without, at the same time, interfering with the free access of gas to the spark for ignition.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a spark plug for, internal combustion engines, in combination with the engine cylinder, a tubular metal plug passed through the cylinder walls and having lateral openings through its walls inside of the cylinder, an insulating core in the plug from the outer end to a point inside of the cylinder walls, a .1netallic wire passing through said core lengthwise and terminating between the lateral openings through the walls of the plug, an insulating core in the inner end of the plug arranged to form an open space in the plug between the adjacent ends of the two insulating cores, a metal rod anchored in said inner insulating core and extending to within electric sparking distance of the inner end of the wire in the body core of the plug, thence bent and extending to within electric sparking distance of the inner surface of the metallic body of the plug so as to produce two sparks within the plug.

2. In combination with an internal conibustion engine cylinder, a tubular netal cas ing passing through into the cylinder and having lateral openings inside of the cylinder, an insulating core extending through 'said metal casing longitudinally from each side of the lateral openings to the respective ends of the casing, an electric conductor passing through the insulating cores from each end of the casing and coming within electric sparking distance of each other between the ends of the cores, and the conductor from the inner insulating core bent and extending to within electric sparking distance of the metal casing to produce two electric sparks within the space in the plug casing. I

Signed at Grand Rapids Michigan December 11, 1914:.

WILLIAM D. VANDECAR. In presence of- I. CILLEY, JOHN W. HILDING. 

